Process for treating iron castings



Patented June 15, 1926.

UNITED STATES PATENT OFFICE.

HARRY A. ENGMAN, JR., OF GOSHEN, INDIANA, ASSIGNOR T ENGMAN RANGE ETER- NAL 00., 0F GOSIIEN, INDIANA, A CORPORATION OF INDIANA.

PROCESS FOR TREATING IRON CASTINGS.

No Drawing. Application filed August 31, 1925. Serial 110.53,?47.

This invention relates to an improved process for treating iron castings.

In the manufacture of iron castings, such as used for stove lids and the like for instance, the practice heretofore has been to anneal the hard iron castings to thus convert them into malleable castings, and to then polish the malleable iron castings to give them the finish desirable for their use as stove lids, or other use for which the castings may be made. It has been found that in the course of time the skin or outer polished surface of the malleable iron castings is broken down or destroyed to a certain extent by rusting or pitting, this being due to V the fact that in polishing the surface of the malleable ,iron casting its resistance to the action of the elements, which causes the rusting and pitting, is lessenec.

One of the objects of the present invention, therefore, is to provide an improved process for treating iron castings of the character referred to whereby the same are provided with polished surfaces having a greater resistance to rust, pitting and other deteriorating actions Without sacrificing any of the desirable properties, results and advantages heretofore realized.

Another object is to provide an improved process for treating iron castings of the character referred to which is simple, Which requires no greater number of steps than the processes practiced heretofore and which may be practiced atno greater cost than is incurred in practicing the processes used heretofore.

vention consists in first polishing the green or hard iron castings, and then annealing the polished hard iron castings to form malleable iron castings. versal of the steps of the old process characterizes the present process and results in the production of polished malleable iron castings possessed of greater rust deterrent properties than castings of this character as heretofore produced.

Although the found tobe particularly useful intreating cast iron stove lids and the like, the process is, of course, of much broader adaptation and may be used in treating iron castings designed for many other and varied purposes.

The invention claimed is 1. The improved process of treating iron castings consisting in first polishing'the casting and then annealing the polished casting to convert it into malleable iron.

2. The improved process of producing polished malleable iron castings which consists in first polishing the green casting and then annealing the same whereby the finished product is rendered more rust resistant.

In Witness whereof I hereto afiix my signature.

HARRY A. ENGMAN, J n.

The improved process of the present in- In other Words, a rep improved process has? been 

